The present invention relates to a connection between a building component in the form of a pipe, a mounting part, a housing or the like and a pipe-shaped line element of metal, wherein the building component has an essentially radially extending, ring-shaped contact surface in the region of its end facing the line element, against which there is clamped a ring-shaped collar that extends essentially parallel to the contact surface, the collar being arranged on the end of the line element and being clamped with the aid of fastening means that grip behind the collar and thereby fit against it.
In such arrangements, the line element can be a plain ended pipe, in particular a thin-walled pipe. However, the line element may be corrugated pipe, be a corrugated hose or a corrugated sheathing hose with spiral or ring-shaped undulations. As a rule, the line element has a circular cylindrical cross section, but other cross sections for the connection, in particular oval shapes, may be provided.
The building component may, for example, be a pipe, a mounting part, a housing or the like. More specifically, one can point to the valve housing of an arrangement for recycling exhaust gases, where a hot and aggressive exhaust gas flows through the line element and thus also the connection. Not only must the line element be temperature and corrosion resistant in this case, but the connection must also be absolutely leakproof to prevent the escape of exhaust gases.
For a connection of the type as described above, the collar is clamped against the contact surface of the building component. If the building component is provided with a flange at the end, this can be done by permitting a flange ring to grip behind the collar, which is then braced with the aforementioned flange, for example through screws. Alternatively the building component may have a ring-shaped thickening at the end or in the end region with essentially trapezoid axial cross section. The correspondingly slanted collar is placed beside the slanted surface of this thickening that faces the line element, wherein the total unit is then gripped, for example, by a clamp with a V-shaped cross section. By tightening the clamp, the thickening and the collar are pressed together axially. Another alternative is the provision of a screw connection between the housing and a nut, which tensions the collar against the contact surface.
In one example of such a connection, a ring-shaped seal ring is inserted between seating surface and collar to produce the necessary seal. However, this raises the costs for the connection and requires particular attention and additional measures when producing the connection because this component is easily lost.
Attempts have also been made to counter this by stamping a circular, axially projecting crimp into the collar. Even with this, however, a complete seal cannot be achieved with certainty because the crimp is again flattened by the tension forces generated when the connection is made, wherein dislocations or a folding of the material that forms the collar occur, which in particular stand in the way of a hermetic seal. This is especially true if the line element, and thus as a rule also the collar, have particularly thin walls for reasons of flexibility, where such a crimp hardly provides a significant internal stiffness.
It is, therefore, the object of the present invention to improve a connection of the above described type in such a way that it meets the requirements of a complete seal, without requiring an additional seal, but which at the same time has a simple, cost-effective and stable design.